Steam-engine indicator



A. C. MEADY.

Patented Dec. 2O

STEAM .ENGINE INDICATOR.

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UNITED STATES -PlrrENTi` OFFICEO ALBERT CECIL MEADY, OF SOMERVILLE, ASSIGNOR TO THE CROSBY STEAM GAGE AND VALVE COMPANY, OF BOSTON, MASSACHUSETTS.

STEAM=ENGINE INDICATOR.

SPECIFICATION forming part of Letters Patent No. 375,086, dated December 20, 1887.

Application tiled July 25, 18H7. Serial No. 245,203.

.To all whom, it may concern:

Be it known that I, ALBERT CEciL MEADY, a citizen of the United States, residing at Somerville, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Steam-En gine Indicators; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to' the accompanying drawings, and to theletters and figures of reference marked thercon,which form a part of this specification.

Figure l is a top view, Fig. 2 a side elevation,l Fig. 3 a vertical section, and Fig. 4 a horizontal section, of the drum, drumspring, the papersustaining cylinder, and a portion of the arm supporting the parts mentioned of a steam-engine indicator having my invention applied thereto. Fig. 5 is a side elevation of the drum.

My invention consists in forming the drum with a vertical groove in its side to receive a vertical ridge formed on the interior' surface of the paper-sustaining cylinder, said cylinder also having a vertical groove formed in its outer surface directly opposite the ridge on its interior to receive au arm pivoted to a head secured to the lower' part of the papersustaining cylinder, said arm at its upper end to operate a spring-latch and be held by it in contact with the groove.

In the drawings, A denotes the arm of the indicator, which supports the spindle a, on which the reciprocating drum B is sustained, the drum having secured to its head the spring S, and the spring being applied to the top of the spindle in the usual manner, as Shown. The Said drum I provide with a vertical groove in its periphery, as shown at b, to receive a vertical ridge, c, projecting inward from the interior surface of the papersustaining cylinder C, said groove and ridge serving to couple the drum and cylinder together.

The cylinder C is made of thin nietal,'as shown, and the ridge c is formed by forcing (No model.)

in a narrow portion of its outer surface throughout the entire length of it toward the axis of the cylinder, thus forming at one and the same time a ridge on its interior surface and a groove in its outer surface,`as shown at d. In said groove I arrange an arm, D, which is pivoted at its lower end at fto a head, E, secured to the cylinder C by screws e e, which enter the lower portion of the groove d.

Near the upper part of the ridge c is secured a spring, g, provided with a catch, 7L, which, when in the position shown in Fig. 3,

vsecurely holds the arm D in contact with the groove d.

The purpose of my invention is to provide a convenient and efficient means of securing to the surface of the cylinder C a sheet of paper to be operated upon by the marker of the indicator when using said indicator to ascertain the pressure of steam in the cylinder of the engine at different points of the stroke of its piston.

By lifting the catch h and swinging the arm D into the position shown in dotted lines in Fig. 3, and applying to the surface of the drum a sheet of paper, so as to envelop the saine and have each end of the sheet lap past the other end in front of the groove d, as shown inl Fig. 2, then, by swinging the said arm under the catch and into the groove into the position shown in full lines in Fig. 8, I shall have a sheet of paper properly secured to the cylinder to be used for the purpose indicated.

Having described my invention ,what I claim in a steam-engine indicator is 1. The cylinder C, provided with the ridge c and groove d, as shown, the head E, secured to said cylinder by screws entering in said groove, and having the arm D pivoted thereto, and the spring g, formed with a catch to hold the arm in contact with the groove, in combination with the reciprocating drum B, having a groove, b, to receive the said ridge c, allessentially as set forth.

2. The cylinder C, provided with the ridge c and groove d, as shown, the head E, secured to said cylinder by screws entering the said groove, and having the arm D pivoted thereto, In testimony whereof I afix my signature in and the spring g, formed with a catch to hold presence of two witnesses. the arm in contact With the groove, in combination with the reciprocating drum B, having a ALBERT GECIL MEADY. 5 groove to receive the ridge of the cylinder C,

the spring S, spindle a, and arm A, all being Witnesses: arranged and to operate substantially as S. N. PIPER, shown and described. WILBUR A. DODGE. 

